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进行了Ti和Ti+Nb超低碳BH钢的铁素体区热轧以及冷轧、退火实验。结果表明,两种超低碳BH钢铁素体区热轧后纵截面晶粒均明显拉长成纤维状,接近冷轧态组织,只有少量等轴晶粒。经后续冷轧和高温盐浴连续退火后均发生了再结晶,形成了等轴铁素体晶粒。两种超低碳BH钢的热轧、冷轧和退火织构均在{111}<121>和{111}<112>处具有峰值,Ti-ULC-BH钢退火板纤维织构组分在{111}<112>处强度最大为16,Ti+Nb-ULC-BH钢退火板纤维织构组分在{111}<121>处强度最大为11,这与反映深冲性能的r值高低相一致。EBSD微观取向分析结果表明,两种超低碳BH钢退火板的铁素体晶粒间微观取向主要是以大角度晶界(>15°)为主,晶界取向差均主要分布在25°～60°;Ti-ULC-BH钢退火板织构中<111>织构占到了75.7%;Ti+Nb-ULC-BH钢退火板织构中<111>织构占60.5%。
The ferritic hot rolling and cold rolling and annealing experiments of Ti and Ti + Nb ultra low carbon BH steel were carried out. The results show that the grains in the longitudinal section of the two kinds of ultra-low carbon BH steel after hot rolling obviously elongate into a fibrous shape, close to the cold-rolled microstructure with only a few equiaxed grains. After subsequent cold rolling and high temperature salt bath continuous annealing recrystallization occurred, forming the equiaxed ferrite grains. The hot-rolled, cold-rolled and annealed textures of the two ultra-low carbon BH steel all have peaks at {111} <121> and {111} <112>. The textures of Ti-ULC- The maximum strength of {111} <112> is 16, and the maximum of the texture of Ti + Nb-ULC-BH steel annealed sheet is 11 at {111} <121> Consistent. The results of EBSD micro-orientation analysis show that the micro-orientations of ferrite grains in the two ultra-low carbon BH annealed sheets are mainly in the high-angle grain boundaries (> 15 °) and the grain boundaries are mainly distributed in the 25 ° ~ 60 °; the texture of Ti-ULC-BH annealed sheet accounted for 75.7% of the texture; the texture of Ti-Nb-ULC-BH annealed sheet accounted for 60.5%.